Introduce master output class and make use of wl_global_remove
There are two big changes.
The first one is a refactoring of our Server API to provide a single access point for compositors to deal with output representations on the Wayland side. The second is that we now make use of wl_global_remove which is available since libwayland 1.18 and allows us to mitigate an accidental racy design in libwayland by delaying the destruction of wl_globals.
- Previous Output class is renamed to WlOutput.
- Legacy remote-access protocol and API is removed.
- Create new Output class that bundles all API for the now dependent classes WlOutput, XdgOutput and OutputDeviceV1.
- State changes are double-buffered, applied atomically.
- Enabling and disabling an output creates and destroys wl_output and xdg-output protocol objects automatically.
- Client scale is calculated automatically from logical size and mode size.
- Require libwayland 1.18 for wl_global_remove.
- Separate Bind class is introduced that represents the bind of a client to a global.
sendfunctions become free functions that can be used from Bind and Resource classes independently.
- Functionality in regards to binds is removed from Resource class.
- Introduce Nucleus class for Global objects.
- A Nucleus instance contains all client-side relevant information.
- Contains in particular the capsule for the wl_global object.
- Lives on after the wl_global has been removed. Is destroyed when the delay timer runs out or the Display goes down.
- Checks on every bind and callback what state the wl_global is in (active, removed, destroyed) and accordingly guards against use after free.
- Relevant test is enabled again to prove our wl_global_remove implementation is working correctly.